/* 肯请高手帮忙
--------------------------------------------
这是从机的中断接收程序,不知为什么,主机在
发送地址后,要延时一段时间,再发数据,而数据之间
不用延时,如果地址后不延时则从机接收不可靠,
有时不正常,BPS2400也不高,AT89C2051@11.0592MHZ.
主机C8051F020@24MHZ BPS2400有点误差但是很小,
好象是2403.
基本通信格式 : 从机地址+0x0d+命令+帧长(仅数据长度)+数据0+数据1...
--------------------------------------------
*/
uchar rxf; // 接收状态
uchar rxn; // 接收数量
uchar address; // 从机地址
bit isr_receive_ok; // 1=中断接收一帧完整数据
sbit TX_EN = P1^1; // 1=发送, 0=接收
void isr_uart(void) interrupt 4
{
uchar x;
bit b;
//---------------------------------
// 发送应答命令数据
if(TI){
TI = 0;
if(txx != txy){
SBUF = ack_buffer[txx];
txx++;
}else{
TX_EN = 0;
receive_error = 0;
}
}
//---------------------------------
// 接收
if(RI){
x = SBUF;
b = RB8;
RI = 0;
if(rxf && RB8){
isr_receive_ok = 0;
SM2 = 1;
rxf = 0;
return;
}
switch(rxf){
case 0:
// LED = 0;
if(x == address){
SM2 = 0;
rxf++;
}
break;
case 1:
if(x == 0x0d){
rxf++;
}else{
SM2 = 1;
rxf--;
}
break;
case 2:
if(isr_receive_ok){
SM2 = 1;
rxf = 0;
}else{
Rxdata2[2] = x;
rxf++;
}
break;
case 3:
if(!x){
isr_receive_ok = 1;
}else{
Rxdata2[3] = x;
rxn = 0;
rxf++;
}
break;
case 4:
Rxdata2[4+rxn] = x;
if(++rxn >= Rxdata2[3]){
SM2 = 1;
rxf = 0;
isr_receive_ok = 1;
}
break;
default:
case 5:
TX_EN = 0;
SM2 = 1;
rxf = 0;
break;
}
}
//---------------------------------------
// 应答当前正在执行的命令
if(isr_receive_ok){
SM2 = 1;
rxf = 0;
if(Rxdata2[2] == ACK_CMD){
ack_buffer[0] = 0x11;
ack_buffer[1] = 0x0d;
ack_buffer[2] = Rxdata[2];
ack_buffer[3] = 2;
ack_buffer[4] = receive_ok;
ack_buffer[5] = address;
// ack_buffer[6] = receive_error;
TX_EN = 1;
txx = 0; txy = 6;
TI = 1;
isr_receive_ok = 0;
}else if(receive_ok){
isr_receive_ok = 0;
receive_error = 1;
}
}
}
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